The last decommissioned single-space parking meter, in use since 1951, has been removed from Manhattan. Some of the decommissioned meters, now stored below the Queensboro Bridge, will be auctioned off. Read more about it here.

DOT has completed replacing all single space parking meters in Manhattan and began installing muni-meters in the Bronx, Brooklyn, Queens and Staten Island this summer. The installation work will be complete by the end of June, 2012.
Muni-meters have several advantages over single-space parking meters, include the convenience of a pay-and-display system, the reduction of unnecessary sidewalk encumbrances, and additional capacity for parked cars in the same curb space.
From nyc.gov